Z-DEVD-FMK is a cell-permeable, irreversible inhibitor of caspases, particularly effective against caspase-3 and caspase-7. It is widely used in research to suppress apoptosis, allowing scientists to study cell death pathways and the role of specific caspases in various biological processes. By inhibiting these key executioner caspases, Z-DEVD-FMK helps prevent the cleavage of cellular substrates that lead to apoptotic cell death. This makes it a valuable tool in experiments involving neurodegenerative diseases, ischemia-reperfusion injury, and other conditions where apoptosis contributes to tissue damage. It is also used to assess the involvement of caspase activity in signaling pathways and to validate the specificity of apoptosis assays. Due to its irreversible binding, it provides sustained inhibition, making it suitable for both in vitro and in vivo studies where prolonged suppression of caspase activity is needed.